According to someone over on 4chan, this is the cover art that is being used for Tyranid codex. The pic floating around is this with some words that look like they were just thrown on the page.
To check out the pic, just follow the link on over to Warseer.
http://www.warseer.com/forums/showthread.php?380107-Tyranid-Codex
The art is a partial by Jon Sullivan for the Catechism of Hate novel from the Black Library. So highly unlikely that this anything.